1. Field of the Invention
The present invention relates to a print head control device for controlling the operation of the print head of a wire dot printer, provided with printing wires driven by piezoelectric elements, i.e., magnetostrictive elements.
Further increase of the printing speed of the wire dot printer has been desired and efforts have been made to develop a wire dot printer provided with a print head provided with printing wires driven by piezoelectric elements.
2. Description of the Prior Art
A wire dot printer of such a type is proposed in Japanese Unexamined Patent Publication (Kokai) No. 2-241754. The wire dot printer selects a printing wire to be driven for printing from print data received from an external device, determines a charging period for charging piezoelectric elements for driving the selected printing wire and a discharging period for discharging the same piezoelectric elements, and charges and discharges the piezoelectric elements for the charging period and the discharge period, respectively. When charged and discharged, the piezoelectric elements drive the corresponding printing wire by its piezoelectric effect to print a dot on a sheet.
In some cases, the printing wire prints a ghost dot due to a rebounding action caused by kinetic energy. The printing wire is liable to print ghost dots when the wire is driven for a plurality of consecutive printing cycles. Ghost dots have a negative effect on print quality.